The present invention relates generally to the irrigation of areas and in particular to cycles of irrigation start and cessation for optimizing irrigation efficiency.
In a previous U.S. Pat. No. 5,341,831, hereafter ""831, incorporated herewith in whole by reference, the inventor B. Zur described an irrigation control method and apparatus. Many other patents refer to irrigation automation but only ""831 implements wetting front depth detection. However, time proved that the implementation disclosed by Zur was more of academic value but less valuable for use in the field.
The advance of the wetting front curves referred to in ""831 as FIGS. 1 and 2, and the formula for the ratio of ZI over ZF, including parameters such as water contents, velocity and rate of water application, are not straightforward enough for practical use.
Furthermore, the apparatus for measuring the progress of the wetting front, shown in ""831 as FIGS. 3 and 4, is better classified as laboratory equipment, not suited for rough field life. The many parts including rather fragile hydrophilic porous elements, assembled on a single thin bolt, are not sturdy enough to comply with heavy-duty outdoors requirements.
It is therefore desirable to provide a user with a simple push-button method and sturdy reliable equipment for easy start and automatic operation.
It is therefore necessary to provide a method for efficient use of irrigation water, and to implement a wetting-front depth probe for use with such irrigation method. Furthermore, it is also beneficial to implement the method for use with large irrigation systems for water saving purposes.
It is an object of the present invention to provide a method for the efficient use of irrigation water and to disclose the implementation of such a method for the realization of a probe for the detection of a wetting-front depth and for the implementation of large irrigation systems.
It is also an object of the present invention to provide a system for irrigation of an area by a plurality of successive adaptive irrigation cycles starting with a first irrigation cycle, the system comprising:
an irrigation controller for initiating and stopping irrigation in response to signals,
a probe having sensors for detecting arrival of a wetting front, the probe providing signals associated with the detected wetting front depth,
a cycler comprising a processor, a memory and an I/O unit, the cycler being coupled to the irrigation controller for emitting signals thereto, and the cycler being coupled to the probe for emitting and for receiving signals therefrom,
a computer program preloaded in the memory of the processor and running on the processor, the processor controlling adaptive irrigation and managing successive irrigation cycles, and the computer program comprising:
a predetermined threshold limit xcex94R, and
a predetermined ratio G1 representing soil texture characteristics.
It is a further object of the present invention to provide a system wherein the computer program further comprises:
a first initial wetting front depth value ZI1 to initiate and stop the first irrigation cycle, and
a procedure for beginning the first adaptive irrigation cycle to be followed by a plurality of successive adapted irrigation cycles.
It is another object of the present invention to provide system wherein both the predetermined threshold limit xcex94R and the ratio G1 are selected, in combination, from the group consisting of preset default values and of user-selected inputs.
It is moreover an object of the present invention to provide a system wherein the computer program further comprises:
a first set of instructions for performing preliminary setup for the first irrigation cycle, and
a second set of instructions for initiating irrigation, for tracking a wetting front depth and for stopping irrigation.
It is furthermore an object of the present invention to provide a system wherein the computer program comprises:
a third set of instructions for deriving information from a preceding irrigation cycle and for adapting instructions for application to a next irrigation cycle, and
a fourth set of instructions for beginning the next irrigation cycle and returning to the second set of instructions.
It is yet a further object of the present invention to provide a system wherein the first set of instructions further comprises a first initial wetting front depth instruction for the first irrigation cycle i=1, for calculating a first initial wetting front depth ZIi , to stop irrigation, by the equation ZIi=Gi*ZFi, where ZF is a final wetting front depth input value selected for optimal irrigation.
It is yet another object of the present invention to provide a system wherein the second set of instructions further comprises:
an irrigation start instruction sent by the processor to the irrigation controller for commanding the irrigation controller to start an irrigation cycle,
a tracking instruction for tracking the wetting front depth by deriving wetting front depth signals from the probe,
a detection instruction for detecting a depth signal received by the processor from the probe, the depth signal indicating arrival of the wetting front to the initial depth of irrigation, and
an irrigation stop instruction sent by the processor to the irrigation controller, the stop signal for commanding the irrigation controller to stop irrigation of an irrigation cycle.
It is also an object of the present invention to provide a system wherein the third set of instructions comprises:
a drainage pause instruction commanding an irrigation pause for a duration relative at least to the soil texture ratio Gi adapted by the irrigation cycle,
an actual depth ZF instruction commanding the processor to derive from the probe an actual derived drainage depth ZF of the wetting front,
a comparison instruction for commanding the processor to compare an actually derived drainage depth of the wetting front ZF with the selected final drainage wetting front depth value ZFi,
a recalculation instruction for calculating an adapted initial wetting front depth ZIi, if the actual derived depth of the wetting front ZF differs for more than a predetermined margin from the final drainage depth ZF1, the recalculation instruction adapting the soil texture ratio Gi and the initial depth of irrigation ZIi for a next irrigation cycle, and
a continue instruction for the third set of instructions to continue to the fourth set of instructions when the actual derived depth of the wetting front ZF does not differ for more than a predetermined margin from the final drainage depth ZF1.
It is also another object of the present invention to provide a system wherein the fourth set of instructions comprises:
a dwell instruction commanding the processor to dwell between successive irrigation cycles, the dwell lasting for a duration relative to at least the adapted ratio G, and
an increment instruction commanding the cycler to raise the irrigation cycle number by one and to return to the second set of instructions for starting a next irrigation cycle.
It is also a further object of the present invention to provide a probe for detecting an irrigation wetting-front depth, the probe operating in association with a processor commanding irrigation cycles started and ended by an irrigation controller, the probe comprising:
a monolithic slender dielectric body having a generally smooth symmetrical external surface and a length defining a longitudinal axis, the body extremities consisting of a forward end having a tapered tip and of a rearward end having a head,
a plurality of spaced apart parallel thin electrically conductive electrodes accommodated flush with and girdling the external surface of the probe in perpendicular to and in distribution along the longitudinal axis, and
a circuitry embedded inside the body of the probe, the circuitry including a plurality of electrical leads at least equal in number to the plurality of conductive electrodes, the electrical leads being arranged adjacent the external surface, parallel to the longitudinal axis and in equally distant radial distribution relative thereto, the electrical leads being electrically coupled to the conductive electrodes and the circuitry being coupled to the processor, for the processor to sample the circuitry and derive a wetting-front depth across one pair of conductive electrodes selected out of the plurality of conductive electrodes.
It is one object of the present invention to provide a probe further comprising a coupling electrically linking each single one conductive electrode out of the plurality of conductive electrodes to only one electrical lead out of the plurality of electrical leads.
It is one further object of the present invention to provide a probe further comprising an insulation for electrically insulating each single one conductive lead out of the plurality of conductive electrodes coupled to one out of the plurality of conductive leads.
It is one other object of the present invention to provide a probe wherein each pair of two adjacent conductive electrodes out of the plurality of conductive electrodes is amenable to form a sensor and to be sampled by the processor.
It is still an object of the present invention to provide a probe wherein the plurality of conductive electrodes is grouped in sets, each set including one pair of adjacent conductive electrodes, and each set being amenable to form a sensor and to be sampled by the processor.
It is still a further object of the present invention to provide a probe wherein any pair of conductive electrodes out of the plurality of conductive electrodes is amenable to form a sensor and to be sampled by the processor.
It is still another object of the present invention to provide a probe wherein the plurality of electrodes is configured for detecting change in soil properties to detect arrival of a wetting front by use of a detection method, selected from the detection methods including impedance, capacitance, radiation and resistance.
It is an additional object of the present invention to provide a probe wherein the plurality of conductive electrodes contacts the soil when the probe is inserted in the ground.
It is a supplementary object of the present invention to provide a probe wherein the monolithic slender dielectric body is made from plastic material.
It is yet an additional object of the present invention to provide a probe wherein the monolithic slender dielectric solid body is extruded.
It is yet a supplementary object of the present invention to provide a method for irrigation of an area by a plurality of successive adaptive irrigation cycles starting with a first irrigation cycle, the method comprising the steps of:
initiating and stopping irrigation with an irrigation controller responsive to signals,
detecting arrival of a wetting front with a probe having sensors, the probe providing signals associated with the detected wetting front depth,
operating a cycler comprising a processor, a memory and an I/O unit, the cycler being coupled to the irrigation controller for emitting signals thereto, and the cycler being coupled to the probe for emitting and for receiving signals therefrom,
running on the processor a computer program preloaded in the memory of the processor, the processor controlling adaptive irrigation and managing successive irrigation cycles, the computer program comprising:
a predetermined threshold limit xcex94R, and
a predetermined ratio G1 representing soil texture characteristics.
It is also an additional object of the present invention to provide a method wherein the computer program further comprising the steps of:
using a first initial wetting front depth value ZI1 to initiate and stop the first irrigation cycle, and
running a procedure for beginning the first adaptive irrigation cycle to be followed by a plurality of successive adapted irrigation cycles.
It is also a further object of the present invention to provide a method wherein both the predetermined threshold limit xcex94R and the ratio G1 are selected, in combination, from the group consisting of preset default values and of user-selected inputs.
It is also a supplementary object of the present invention to provide a method wherein the computer program further comprises the steps of:
running a first set of instructions for performing preliminary setup for the first irrigation cycle, and
running a second set of instructions for initiating irrigation, for tracking a wetting front depth and for stopping irrigation.
It is one additional object of the present invention to provide a method wherein the computer program further comprises the steps of:
running a third set of instructions for deriving information from a preceding irrigation cycle and for adapting instructions for application to a next irrigation cycle, and
running a fourth set of instructions for beginning the next irrigation cycle and returning to the second set of instructions.
It is one supplementary object of the present invention to provide a method wherein the first set of instructions further comprises the steps of using a first initial wetting front depth instruction for the first irrigation cycle i=1, for calculating a first initial wetting front depth ZIi, to stop irrigation, by the equation ZIi=Gi*ZFi, where ZF is a final wetting front depth input value selected for optimal irrigation.
It is still an additional object of the present invention to provide a method wherein the second set of instructions further comprises the steps of:
detecting an irrigation start instruction sent by the processor to the irrigation controller for commanding the irrigation controller to start an irrigation cycle, a tracking instruction for tracking the wetting front depth by deriving wetting front depth signals from the probe,
inserting a detection instruction for detecting a depth signal received by the processor from the probe, the depth signal indicating arrival of the wetting front to the initial depth of irrigation, and
reading an irrigation stop instruction sent by the processor to the irrigation controller, the stop signal for commanding the irrigation controller to stop irrigation of an irrigation cycle.
It is still a supplementary object of the present invention to provide a method wherein the third set of instructions further comprises the steps of:
executing a drainage pause instruction commanding an irrigation pause for a duration relative at least to the soil texture ratio Gi adapted by the irrigation cycle,
reading an actual depth ZF instruction commanding the processor to derive from the probe an actual derived drainage depth ZF of the wetting front,
implementing a comparison instruction for commanding the processor to compare an actually derived drainage depth of the wetting front ZF with the selected final drainage wetting front depth value ZFi,
calculating an adapted initial wetting front depth ZIi, with a recalculation instruction if the actual derived depth of the wetting front ZF differs for more than a predetermined margin from the final drainage depth ZF1, the recalculation instruction adapting the soil texture ratio Gi and the initial depth of irrigation ZIi for a next irrigation cycle, and
applying a continue instruction for the third set of instructions to continue to the fourth set of instructions when the actual derived depth of the wetting front ZF does not differ for more than a predetermined margin from the final drainage depth ZF1.
It is still a further additional object of the present invention to provide a method wherein the fourth set of instructions comprises the steps of:
executing a dwell instruction commanding the processor to dwell between successive irrigation cycles, the dwell lasting for a duration relative to at least the adapted ratio Gi, and
effecting an increment instruction commanding the cycler to raise the irrigation cycle number by one and to return to the second set of instructions for starting a next irrigation cycle.